Despite improvements in therapeutic approaches like immunotherapy and gene therapy, cancer still remains a serious threat to world health due to its high incidence and mortality rates. Limitations of conventional therapy include suboptimal targeting, multidrug resistance, and systemic toxicity. A major challenge in current oncology therapies is the development of new delivery methods for antineoplastic drugs that act directly on target. One approach involves the complexation of antitumor drugs with cyclodextrins (CDs) and chitosan (CS) as an attempt to counteract their primary limitations: low water solubility and bioavailability, diminished in vitro and in vivo stability, and high dose-dependent toxicity. All those drawbacks may potentially exclude some therapeutic candidates from clinical trials, thus their integration into smart delivery systems or drug-targeting technologies must be implemented. We intended to overview new drug delivery systems based on chitosan or cyclodextrins with regard to the current diagnosis and cancer management. This narrative review encompasses full-length articles published in English between 2019 and 2025 (including online ahead of print versions) in PubMed-indexed journals, focusing on recent research on the encapsulation of diverse antitumor drugs within those nanosystems that exhibit responsiveness to various stimuli such as pH, redox potential, and folate receptor levels, thereby enhancing the release of bioactive compounds at tumor sites. The majority of the cited references focus on the most notable research, studies of novel applications, and scientific advancements in the field of nanostructures and functional materials employed in oncological therapies over the last six years. Certainly, there are additional stimuli with research potential that can facilitate the drug’s release upon activation, such as reactive oxygen species (ROS), various enzymes, ATP level, or hypoxia; however, our review exclusively addresses the aforementioned stimuli presented in a comprehensive manner.

Starting from indomethacin (IND), one of the most prescribed non-steroidal anti-inflammatory drugs (NSAIDs), new nitric oxide-releasing indomethacin derivatives with 1,3,4-oxadiazole-2-thiol scaffold (NO-IND-OXDs, 8a–p) have been developed as a safer and more efficient multitarget therapeutic strategy. The successful synthesis of designed compounds (intermediaries and finals) was proved by complete spectroscopic analyses. In order to study the in silico interaction of NO-IND-OXDs with cyclooxygenase isoenzymes, a molecular docking study, using AutoDock 4.2.6 software, was performed. Moreover, their biological characterization, based on in vitro assays, in terms of thermal denaturation of serum proteins, antioxidant effects and the NO releasing capacity, was also performed. Based on docking results, 8k, 8l and 8m proved to be the best interaction for the COX-2 (cyclooxygense-2) target site, with an improved docking score compared with celecoxib. Referring to the thermal denaturation of serum proteins and antioxidant effects, all the tested compounds were more active than IND and aspirin, used as references. In addition, the compounds 8c, 8h, 8i, 8m, 8n and 8o showed increased capacity to release NO, which means they are safer in terms of gastrointestinal side effects.

Wound management represents a continuous challenge for health systems worldwide, considering the growing incidence of wound-related comorbidities, such as diabetes, high blood pressure, obesity, and autoimmune diseases. In this context, hydrogels are considered viable options since they mimic the skin structure and promote autolysis and growth factor synthesis. Unfortunately, hydrogels are associated with several drawbacks, such as low mechanical strength and the potential toxicity of byproducts released after crosslinking reactions. To overcome these aspects, in this study new smart chitosan (CS)-based hydrogels were developed, using oxidized chitosan (oxCS) and hyaluronic acid (oxHA) as nontoxic crosslinkers. Three active product ingredients (APIs) (fusidic acid, allantoin, and coenzyme Q10), with proven biological effects, were considered for inclusion in the 3D polymer matrix. Therefore, six API-CS-oxCS/oxHA hydrogels were obtained. The presence of dynamic imino bonds in the hydrogels’ structure, which supports their self-healing and self-adapting properties, was confirmed by spectral methods. The hydrogels were characterized by SEM, swelling degree, pH, and the internal organization of the 3D matrix was studied by rheological behavior. Moreover, the cytotoxicity degree and the antimicrobial effects were also investigated. In conclusion, the developed API-CS-oxCS/oxHA hydrogels have real potential as smart materials in wound management, based on their self-healing and self-adapting properties, as well as on the benefits of APIs.

In the past many research studies have focused on the thiazolidine-4-one scaffold, due to the important biological effects associated with its heterocycle. This scaffold is present in the structure of many synthetic compounds, which showed significant biological effects such as antimicrobial, antifungal, antioxidant, anti-inflammatory, analgesic, antidiabetic effects. It was also identified in natural compounds, such as actithiazic acid, isolated from Streptomyces strains. Starting from this scaffold new xanthine derivatives have been synthetized and evaluated for their antibacterial and antifungal effects. The antibacterial action was investigated against Gram positive (Staphyloccoccus aureus ATCC 25923, Sarcina lutea ATCC 9341) and Gram negative (Escherichia coli ATCC 25922) bacterial strains. The antifungal potential was investigated against Candida spp. (Candida albicans ATCC 10231, Candida glabrata ATCC MYA 2950, Candida parapsilosis ATCC 22019). In order to improve the antimicrobial activity, the most active xanthine derivatives with thiazolidine-4-one scaffold (XTDs: 6c, 6e, 6f, 6k) were included in a chitosan based polymeric matrix (CS). The developed polymeric systems (CS-XTDs) were characterized in terms of morphological (aspect, particle size), physic-chemical properties (swelling degree), antibacterial and antifungal activities, toxicity, and biological functions (bioactive compounds loading, entrapment efficiency). The presence of xanthine-thiazolidine-4-one derivatives into the chitosan matrix was confirmed using Fourier transform infrared (FT-IR) analysis. The size of developed polymeric systems, CS-XTDs, ranged between 614 µm and 855 µm, in a dry state. The XTDs were encapsulated into the chitosan matrix with very good loading efficiency, the highest entrapment efficiency being recorded for CS-6k, which ranged between 87.86 ± 1.25% and 93.91 ± 1.41%, depending of the concentration of 6k. The CS-XTDs systems showed an improved antimicrobial effect with respect to the corresponding XTDs. Good results were obtained for CS-6f, for which the effects on Staphylococcus aureus ATCC 25923 (21.2 ± 0.43 mm) and Sarcina lutea ATCC 9341 (25.1 ± 0.28 mm) were comparable with those of ciprofloxacin (25.1 ± 0.08 mm/25.0 ± 0.1 mm), which were used as the control. The CS-6f showed a notable antifungal effect, especially on Candida parapsilosis ATCC 22019 (18.4 ± 0.42 mm), the effect being comparable to those of nystatin (20.1 ± 0.09 mm), used as the control. Based on the obtained results these polymeric systems, consisting of thiazolidine-4-one derivatives loaded with chitosan microparticles, could have important applications in the food field as multifunctional (antimicrobial, antifungal, antioxidant) packaging materials.

In this study we present design and synthesis of nineteen new nitric oxide-releasing indomethacin derivatives with 1,3-thiazolidine-4-one scaffold (NO-IND-TZDs) (6a-s), as a new safer and efficient multi-targets strategy for inflammatory diseases. The chemical structure of all synthesized derivatives (intermediaries and finals) was proved by NMR and mass spectroscopic analysis. In order to study the selectivity of NO-IND-TZDs for COX isoenzymes (COX-1 and COX-2) a molecular docking study was performed using AutoDock 4.2.6 software. Based on docking results, COX-2 inhibitors were designed and 6o appears as the most selective derivative which showed an improved selective index compared with indomethacin (IND) and diclofenac (DCF), used as reference drugs. The biological evaluation of 6a-s, using in vitro assays has included the anti-inflammatory and antioxidant effects as well as the nitric oxide (NO) release. Referring to the anti-inflammatory effects, the most active compound was 6i, which was more active than IND and aspirin (ASP) in term of denaturation effect, on bovine serum albumin (BSA), as indirect assay to predict the anti-inflammatory effect. An appreciable anti-inflammatory effect, in reference with IND and ASP, was also showed by 6k, 6c, 6q, 6o, 6j, 6d. The antioxidant assay revealed the compound 6n as the most active, being 100 times more active than IND. The compound 6n showed also the most increase capacity to release NO, which means is safer in terms of gastro-intestinal side effects. The ADME-Tox study revealed also that the NO-IND-TZDs are generally proper for oral administration, having optimal physico-chemical and ADME properties. We can conclude that the compounds 6i and 6n are promising agents and could be included in further investigations to study in more detail their pharmaco-toxicological profile.

Type 2 diabetes mellitus (T2DM) is one of the most common metabolic disorders, with a major involvement of oxidative stress in its onset and progression. Pioglitazone (Pio) is an antidiabetic drug that mainly works by reducing insulin resistance, while curcumin (Cur) is a powerful antioxidant with an important hypoglycemic effect. Both drugs are associated with several drawbacks, such as reduced bioavailability and a short half-life time (Pio), as well as instability and poor water solubility (Cur), which limit their therapeutic use. In order to overcome these disadvantages, new co-delivery (Pio and Cur) chitosan-based nanoparticles (CS-Pio-Cur NPs) were developed and compared with simple NPs (CS-Pio/CS-Cur NPs). The NPs were characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). In addition, the entrapment efficiency (EE) and loading capacity (LC), as well as the release profile, of the APIs (Pio and Cur) from the CS-APIs NPs in simulated fluids (SGF, SIF, and SCF) were also assessed. All the CS-APIs NPs presented a small particle size (PS) (211.6–337.4 nm), a proper polydispersity index (PI) (0.104 and 0.289), and a positive zeta potential (ZP) (21.83 mV–32.64 mV). Based on the TEM results, an amorphous state could be attributed to the CA-APIs NPs, and the TEM analysis showed a spherical shape with a nanometric size for the CS-Pio-Cur NPs. The FT-IR spectroscopy supported the successful loading of the APIs into the CS matrix and proved some interactions between the APIs and CS. The CS-Pio-Cur NPs presented increased or similar EE (85.76% ± 4.89 for Cur; 92.16% ± 3.79 for Pio) and LC% (23.40% ± 1.62 for Cur; 10.14% ± 0.98 for Pio) values in comparison with simple NPs, CS-Cur NPs (EE = 82.46% ± 1.74; LC = 22.31% ± 0.94), and CS-Pio NPs (EE = 93.67% ± 0.89; LC = 11.24% ± 0.17), respectively. Finally, based on the release profile results, it can be appreciated that the developed co-delivery nanosystem, CS-Pio-Cur NPs, assures a controlled and prolonged release of Pio and Cur from the polymer matrix along the GI tract.